CONTROL & MTG GP-JOYSTICK 1851994 - Caterpillar

Personal injury or death can result from machine articulation or movement.Machine frames can move and a person can be crushed.Connect the steering frame lock link between the front and rear frames before working on machine.
Personal injury or death can result from escaping fluid under pressure.Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.Always use a board or cardboard when checking for a leak.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
This section provides probable causes to known problems. Perform a visual inspection of the machine. Refer to Testing and Adjusting, "Visual Inspection". Prepare the machine for troubleshooting. Refer to Testing and Adjusting, "Machine Preparation for Troubleshooting".Troubleshooting Problem List
Turning the steering wheel is difficult.
The machine does not turn evenly.
The machine does not turn when the steering wheel is turned.
The steering metering pump makes noise and the steering cylinder rod does not move freely.Troubleshooting Probable Causes
Problem 1Turning the steering wheel is difficult.Probable causes
The oil is cold.
The oil is contaminated. Refer to Testing and Adjusting, "Hydraulic Oil Contamination - Test".
There is a restriction in an oil line of the metering pump.
The work tool and steering pump pressure is low. Refer to Testing and Adjusting, "Steering System Pressure - Test".
There is a leak or blockage in the load sensing line.Problem 2The machine does not turn evenly.Probable causes
The oil is contaminated. Refer to Testing and Adjusting, "Hydraulic Oil Contamination - Test".
The metering pump is sticking.
The priority valve spool is sticking.
The steering cylinder is scored.Problem 3The machine does not turn when the steering wheel is turned.Probable causes
The metering pump is damaged.
The priority valve spool is sticking.
There is a mechanical failure in the steering linkage.
The piston seals and/or the steering cylinder is worn. Refer to Testing and Adjusting, "Operational Checks".Problem 4The pump makes noise and the steering cylinder rod does not move freely.Probable causes
The oil level in the hydraulic oil tank is low. Refer to Operation and Maintenance Manual, SEBU7415, "Hydraulic System Oil Level - Check".
There is air in the hydraulic circuit.
There is a loose connection of the oil line on the inlet side of the hydraulic pump.
The viscosity of the oil is incorrect. Refer to Operation and Maintenance Manual, SEBU7415, "Lubricant Viscosities".
The pump has too much wear. Refer to Testing and Adjusting, "Pump Flow - Test".